﻿using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace KeyboardDebounce
{
    public class KeyboardFilter
    {
        private const int WH_KEYBOARD_LL = 13;
        private const int WM_KEYDOWN = 0x0100;
        private static LowLevelKeyboardProc _proc = HookCallback;
        private static IntPtr _hookID = IntPtr.Zero;

        private static Dictionary<Keys, long> _keyTimestamps = new Dictionary<Keys, long>();

        // 日志文件路径（可自定义）
        private static readonly string LogFilePath = Path.Combine(
            AppDomain.CurrentDomain.BaseDirectory, "keypress_blocked.log");

        public static void Start()
        {
            _hookID = SetHook(_proc);
        }

        public static void Stop()
        {
            if (_hookID != IntPtr.Zero)
                UnhookWindowsHookEx(_hookID);
        }

        private static IntPtr SetHook(LowLevelKeyboardProc proc)
        {
            using (Process curProcess = Process.GetCurrentProcess())
            using (ProcessModule curModule = curProcess.MainModule)
            {
                return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
                  GetModuleHandle(curModule.ModuleName), 0);
            }
        }

        private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);

        private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
        {
            if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
            {
                int vkCode = Marshal.ReadInt32(lParam);
                Keys key = (Keys)vkCode;
                long now = DateTimeOffset.Now.ToUnixTimeMilliseconds();

                //if (_keyTimestamps.TryGetValue(key, out long lastTime))
                //{
                //    if (now - lastTime < 100)
                //    {
                //        string log = $"[{DateTime.Now:HH:mm:ss.fff}] 阻止重复按键: {key} ({vkCode})";
                //        Console.WriteLine(log); // 控制台打印
                //        File.AppendAllText(LogFilePath, log + Environment.NewLine); // 文件追加

                //        return (IntPtr)1; // 拦截事件
                //    }
                //}

                if (_keyTimestamps.TryGetValue(key, out long lastTime))
                {
                    bool isModifierKey = key == Keys.Control || key == Keys.Alt ||
                          key == Keys.LControlKey || key == Keys.RControlKey ||
                          key == Keys.Shift || key == Keys.LShiftKey || key == Keys.RShiftKey;

                    if (!isModifierKey && now - lastTime < 100)
                    {
                        string log = $"[{DateTime.Now:HH:mm:ss.fff}] 阻止重复按键: {key} ({vkCode})";
                        Console.WriteLine(log);
                        File.AppendAllText(LogFilePath, log + Environment.NewLine);
                        return (IntPtr)1; // 拦截非组合键重复
                    }
                }

                _keyTimestamps[key] = now;
            }

            return CallNextHookEx(_hookID, nCode, wParam, lParam);
        }

        #region WinAPI Imports
        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr SetWindowsHookEx(int idHook,
            LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern bool UnhookWindowsHookEx(IntPtr hhk);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr CallNextHookEx(IntPtr hhk,
            int nCode, IntPtr wParam, IntPtr lParam);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr GetModuleHandle(string lpModuleName);
        #endregion
    }
}
